Has anyone had success with importing a Rhino model into SAP2000?
I have a model from an architect that I’ve been able to simplify. Now I’m trying to export it and then import it into SAP2000 so I can complete my structural analysis. I don’t need to go back and forth, I just need the geometry to import. I feel like I’m going in circles and all the tutorials I find are too complex for someone as green as me.
Does anyone have a step-by-step suggestion of how I can export this model into the appropriate format so that when I import it into SAP2000, the curves/surfaces/faces will be read appropriately and then I can assign the correct structural property to the area.
I looked at their Web site.
It looks like SAP2000 is a mesh based FEA tool.
I could not find any specific details about what mesh file formats it can import.
Rhino’s Mesh or QuadMesh commands should be useful, then export the resulting mesh to a format SAP2000 can read.
Your particular model geometry is not trivial to transfer. Most structural analysis software are typically supporting planar elements (ie typical walls and slabs), and have limited support for nurbs faces or trims / edge curves. You have a good idealized surface model (rather than say a collection of solid polysurfaces that are not easy to idealize to structural analysis surfaces).
You’ll see some geometry come across if you use IGES export directly from your 3dm file, but it seems to have a hard coded conversion to facet the geometry to planar surfaces (which might or might not be acceptable). And it doesn’t recognize trims on adjacent planar surfaces.
So I would suggest the best approach is to mesh the model in Rhino/Grasshopper. Personally I have used LUSAS or Strand7 to mesh the model even when analyzing the file in more conventional structural analysis software. At Geometry Gym, we do provide tools to facilitate this type of model conversion.
The other option is use Rhino to mesh the geometry. The rhino meshing implementation is primarily focussed on visualization, and with some care it might be possible to generate analysis friendly mesh (but likely not optimal). The difficulty being it’s not practical (in my experience) to get coincident vertex on shared edges when surfaces are not joined. And there isn’t lots of control on transitions, refined meshing at points of interest, aspect ratios and the like that a FE mesher in software such as LUSAS or Strand7 would permit to be configured.
This isn’t as helpful as I’d like to be, certainly if you can get an appropriate mesh in Rhino/Grasshopper, Geometry Gym can help automate the assignment of material, thickness, loading and other attributes by creating a grasshopper script to assign this (if you don’t want to do these steps manually).
One alternative technique is to use Karamba3d to mesh the surfaces. It generates tri mesh (which is often undesirable), but you can then use Grasshopper to detect quads.
Refer attached. I selected a few key surfaces to demonstrate, you could use geometry pipeline to collect all geometry. 221027 karamba mesh to SAP2000.gh (12.0 KB)
